In the deep waters of the Black Sea, scientists found microbes that can make membrane lipids, a layer that surrounds a cell like a skin, of unexpected origin. Researchers from NIOZ and Utrecht University have published their findings in the prestigious ISME Journal.
The current leading theory is that Eukaryotes evolved from a symbiosis event between archaeal and bacterial cells in which the archaeal cell was the host. But how does this work when their ‘skins’ are so different and share no sign of common ancestry?[Researcher Laura] Villanueva: “To explain the creation of more complex life-forms, the archaeal membrane must have made a switch to a bacterial type membrane. Such a switch likely needed a transition period in which the two membrane types were mixed.”
However, mixed lipid membranes had never been found in microbes until the team of Villanueva made an unexpected discovery in the deep waters of the Black Sea.
The peculiarity was also found in the genetic material of other, closely related bacteria and supports the idea that this ability to create ‘mixed’ membranes is more widespread than previously thought.
This discovery sheds new light on the evolution of all cellular life forms and may have important consequences for the interpretation of archaeal lipid fossils in the geological record and paleoclimate reconstructions.